Optical channel status detection refers to disposing optical components at position points on an optical communications network to monitor and measure performance of an optical channel, to obtain a status of the entire optical network, and provide a basis for managing and maintaining the network. A pilot is an important means of detecting a status of an optical channel. Specifically, a process of detecting a status of an optical channel by using a pilot is as follows. A pilot signal is modulated on a transmitted signal on a to-be-detected optical channel, so that the pilot signal is transmitted on the optical network along with the transmitted signal, and then related information about the pilot signal is detected at a status detection point of the optical channel, to determine a current status of the optical channel. The pilot signal has a feature that is consistent with that of the transmitted signal. Therefore, after detection is performed on information such as a frequency and an amplitude of the pilot, current performance information of the transmitted signal on the optical communications network can be learned, that is, the status of the optical channel is determined. An amplitude of the pilot signal corresponds to power of the transmitted signal in real time, which ensures stability and predictability of a pilot modulation depth, and is a prerequisite for ensuring effective detection on the status of the optical channel.
Currently, to ensure stability and predictability of a pilot modulation depth, power of a service flow signal and power of a pilot on an optical network channel are learned by using a feedback loop, to measure, adjust, and lock the pilot in real time. However, if a pilot signal is loaded, in a digital driver or a Digital Signal Processing (DSP) chip of a transmitter, into the service flow signal in a scrambling manner, and then is modulated by using an Mach-Zehnder (MZ) modulator, the pilot loses, due to a non-linear feature of the MZ modulator, a linear relationship with a pilot feature that is initially applied. A parameter such as an amplitude of the pilot signal cannot be quickly and effectively adjusted by using an existing mechanism. Consequently, a status of the optical channel cannot be correctly detected.